Foliation is the planar arrangement of minerals in deformed metamorphic rocks.
Gneissic Banding - alternating layers of light and dark grains in the rock.
Schistosity - Alignment of platy minerals in the rock.
Cleavage - rock splits parallel to aligned fine grains in the rock.
Classification of FoliationsEdit
A continuous (penetrative) foliation deforms all of the grains in the rock. This can happen with course grains (schist) or fine grains (slate). Another type is a spaced (non-penetrative) foliation which leaves domains of undeformed material within the rock.